GPS navigation, or global positioning system navigation, is a modern invention that allows the tracing or mapping of an area with the use of satellite positioning. This system was developed by Ian Getting and the United States Department of Defense, for military use in navigation and surveillance. Early GPS navigation was done with the use of eighteen satellites in constant communication with ground stations. Since 2007, there have been twenty-four GPS satellites in orbit, forming what is known as the "satellite constellation."
This continuous communication between satellites and ground stations is done through signals that contain information such as time, satellite orbit position, and receiver position. All of the information that is communicated in GPS is interpreted by the receiver to map out a location, path, or to locate an object. GPS navigation has evolved into a highly accurate system that is used by both the military and civilians. Initially, signals sent between the station and the satellite allowed for GPS navigation to be accurate up to a few meters. Today, more advanced systems can pinpoint destinations, routes, or objects with an accuracy of up to a few centimeters.
There are numerous uses for GPS navigation. Some of the common military uses of GPS navigation includes missile guiding systems, surveillance missions, or guiding troops through unfamiliar terrain. Civilian uses for GPS navigation involve receiving direction to a destination and mail or order tracking. GPS navigation availability is constantly increasing as the system is becoming a norm for automobiles and mobile phones.